1. Field of the Invention
The present invention is generally related to heat exchanger assemblies and, more particularly, to heat exchanger assemblies which are formed by bending a planar heat exchanger element into a generally cylindrical shape and connecting two end surfaces of the generally cylindrical heat exchanger element together with specially formed brackets.
2. Description of the Prior Art
Many different types of heat exchanger coils are well known to those skilled in the art. For example, planar heat exchanger assemblies are commonly used in condensers of air conditioning systems. It is also known to combine planar assemblies to form A-coils that are well known for use as evaporators in air conditioning systems. For certain applications, it is also known to bend a generally planar heat exchanger element into a cylindrical shape and direct an air flow radially through the heat exchanger. This type of cylindrical heat exchanger assembly has been used for many years in condenser applications for home air conditioning systems and, more recently, cylindrical evaporators have been developed for inclusion within the plenum chamber of a furnace for use as an evaporator in an air conditioning system.
When planar coils are connected together to form A-coils, they are typically attached to each other or to additional plate components with sheet metal screws or other mechanical fastening techniques. When planar coils are bent to form cylindrical heat exchanger assemblies, opposing end surfaces of the assembly are attached to each other using an intermediate plate surface that is mechanically attached to both brackets on opposing end surfaces of the bent heat exchanger. Although certain non-heat exchanging components have been manufactured which utilize brackets that are shaped to be received in locking association when disposed proximate to each other and placed under a separating force, this technique has not been applied to heat exchangers. Instead, known methods for attaching the opposing end surfaces of cylindrical heat exchangers utilize additional components, such as connector plates, attached between opposing brackets with mechanical fasteners used to connect each bracket to the connector plate.
U.S. Pat. No. 4,340,015, which issued to Wright et al on July 20, 1982, discloses the use of a fastener strip that is shaped to receive specifically bent end portions of a heat exchanger condenser cover. It provides an apparatus for encasing a heat exchanger unit. A wrapper is disclosed which comprises solid portions for structural support of the heat exchanger unit and fastening means including closure means formed on each end of the wrapper with a fastener strip which co-operates with the closure means to secure the wrapper in an appropriate position. While disclosing interlocking bent portions of sheet metal components, this patent requires the use of an additional separate component, such as its fastener strip, to maintain opposing ends of a cover in a predetermined relationship to each other.
U.S. Pat. No. 2,625,804, which issued to Patch et al on Jan. 20, 1953, discloses an over-center latch for maintaining the end surfaces of a cooler band in a predetermined position and maintained the cooler band in a restrictive association with a barrel in a barrel cooling apparatus. The invention relates to a cooling and dispensing device for beverages and, more particularly, describes a device for holding a barrel of beverage in place within the cooling apparatus.
U.S. Pat. No. 3,260,305, which issued to Leonard et al on July 12, 1966, describes a folded radiator design for use in association with a space satellite power plant. The radiators are capable of being wrapped around a generally cylindrical assembly and then unfolded to extend radially away from the cylindrical assembly. This patent does not disclose a means for interlocking the opposing end surfaces of a generally cylindrical heat exchanger.
The field of heat exchanger technology can be significantly enhanced by providing a means for maintaining the end surfaces of a cylindrical heat exchanger in a predetermined association with each other while also simplifying the manufacturing procedure and reducing the total number of components and the total cost required to form a generally cylindrical heat exchanger from a planar heat exchanger element.